The Acer 271HL has a maximum contrast ratio of 100000000:1. That's over five times the contrast ratio of the most frequently found dynamic contrast ratio of 20000000:1.
A 100000000:1 dynamic contrast ratio is actually the best contrast ratio across all PC screens that have been on the market for around the same time as the 271HL.
Across similar types of flatpanel monitor the worst contrast ratio is Mega Contrast.
We think you might also be interested in some of the other PC monitors that have a 100000000:1 dynamic contrast ratio currently available including a cheaper PC monitor such as the Acer B236HL (£139.98) or you might consider a better rated PC monitor such as the Asus VN279 (£239.14).